The present invention relates to a pneumatic bellows for a pneumatic suspension/spring, a pneumatic suspension/spring, a vehicle axle system and a method for manufacturing a pneumatic bellows.
Traditionally, an automotive axle of a commercial vehicle has an axle body that forms an axle unit at one end by means of at least one longitudinal swinging arm and is therefore movably coupled to the vehicle frame and is supported with respect to the vehicle frame by a pneumatic suspension arranged above or behind the area of intersection of the axle body and the longitudinal swinging arm. The pneumatic suspension in turn comprises a pneumatic bellows arranged between a cover and a base plate, whereby a plunger is arranged on the pneumatic bellows for mechanical coupling between the pneumatic bellows on the one hand and the axle unit on the other hand. The pneumatic bellows is connected on its axle-sided area to the plunger, with the outside surface of the plunger serving as a rolling surface for the pneumatic bellows, thereby ensuring a guided movement of the pneumatic bellows during operation in the up-and-down movement of the plunger.
However, such pneumatic suspensions have only limited suitability for crane and rail freight loading because the pneumatic bellows is completely rolled out without any additional holding devices due to the weight of the axle, which is then hanging beneath the vehicle, thereby creating a vacuum with respect to the environment in the pneumatic bellow. When the vehicle is lowered, there is the risk that the pneumatic bellows might collapse inward and/or be tilted and/or collapse toward the plunger and therefore unable to roll over the plunger, which can result in damage.
To overcome this problem, the spring path of the pneumatic suspension in crane and rail freight loading is therefore traditionally limited on the basis of a tensioning device and/or safety device attached to the vehicle frame and/or a divided plunger is used. Alternatively, the pneumatic suspension may also be designed so that the pneumatic suspension is detachably connected to the frame. In crane loading of a trailer by means of a readjusting device, the pneumatic suspension is separated from the frame, and the cover and therefore also the suspension bellows are held in a defined position with respect to the plunger by means of the readjusting device so that the suspension bellows will roll over the plunger and/or be held in an unreeled state.